Home » Fix: “The connection to Microsoft Exchange is unavailable” on Windows 10

Email is an everyday part of our lives, and while some users prefer using webmail services, others are using email clients. One of the most used email clients on Windows 10 is Outlook, but users reported The connection to Microsoft Exchange is unavailable error message while using Outlook, so let’s see how to fix it.

“The connection to Microsoft Exchange is unavailable”, how to fix it?

Fix – “The connection to Microsoft Exchange is unavailable”

Solution 1 – Edit your registry

The connection to Microsoft Exchange is unavailable error usually appears due to problems with your registry. Your registry holds the necessary information that Outlook uses in order to access Microsoft Exchange, and if this information doesn’t exist in your registry, you’ll get The connection to Microsoft Exchange is unavailable error message. To fix this problem, you need to manually add the required data to the registry. Editing registry can be somewhat dangerous and cause certain issues if you don’t do it properly, therefore use caution and create a backup of your registry just in case. Users reported that they fixed this problem by copying the registry key from a working PC and adding it to their registry on the problematic PC. To do that, follow these steps:

Select Microsoft Exchange (send from this account by default) account and click Change.

Click on More Settings.

Microsoft Exchange window will now open. Go to the Security tab.

In the Encryption section check the Encrypt data between Microsoft Office Outlook and Microsoft Exchange and click Apply and OK to save changes.

Click Next and Finish to complete the change.

After making these changes the issue with Microsoft Exchange should be fixed.

Solution 3 – Create a new Outlook profile

Users reported that you can fix The connection to Microsoft Exchange is unavailable error simply by creating a new Outlook profile. To do that, you need to follow these simple steps:

Go to Control Panel and select Mail.

Click on Show Profiles and then click on Add.

In the Profile Name box enter the name for the new profile and click OK.

After creating a new profile, set it as default and check if the error is resolved.

Solution 4 – Delete your Outlook profile

Few users suggest that in order to fix this problem you need to delete your Outlook profile and recreate it. To do that, simply go to Control Panel > Mail and delete your default profile. After deleting the default profile, start Outlook and you’ll be asked to create a new profile. After creating a new profile everything should work without any problems.

When Services window opens, locate Microsoft Exchange service, right click it and choose Restart from the menu. If you have more than one Microsoft Exchange service available, be sure to restart them all.

After Microsoft Exchange service restarts, check if the problem is resolved.

Solution 7 – Disable your antivirus

Using antivirus is crucial for your system’s safety, but sometimes your antivirus software can interfere with Outlook and cause this error to appear. To fix this problem, you need to disable your antivirus and add Outlook and the necessary applications and ports to the list of exclusions. If that doesn’t help, you might want to temporarily remove your antivirus program. Users reported that Malwarebytes was causing this error to appear, but keep in mind that almost any third-party antivirus software can interfere with Outlook and cause this issue.

Solution 8 – Set the WINS IP addresses on your PC

If you’re using a VPN while connecting to the server, you need to set your IP addresses to static. According to users, changing the WINS IP addresses fixes the problem with Microsoft Exchange, therefore be sure to try it if you’re using a VPN.

In the right pane, locate Enable RPC encryption option and double click it.

In the settings window select Enabled and click OK to save changes.

Solution 2 – Export registry keys from a different PC

You can fix this problem simply by exporting registry keys from another PC that runs Outlook 2007. To do that, switch to a different PC and follow these steps:

Open Registry Editor and go to the HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem key in the left pane.

Right click Windows Messaging Subsystem key and choose Export. Enter the name for the export file and save it.

Transfer the exported registry file to the problematic PC and double click it to add it to your registry.

After adding this file to your registry, the problem with Outlook 2007 and Microsoft Exchange should be fixed completely.

Solution 3 – Remove ZeroConfigExchange DWORD from the registry

According to Microsoft, ZeroConfigExchange DWORD can cause this problem with Outlook 2007, but you can fix The connection to Microsoft Exchange is unavailable error simply by removing the problematic DWORD. To do that, follow these steps:

Open Registry Editor.

Go to HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\12.0\Outlook\AutoDiscover key in the left pane.

In the right pane, locate ZeroConfigExchange DWORD, right click it and choose Delete from the menu.

Before you start applying this solution you need to download the latest version of the Outlk14.adm Group Policy template and add it to your domain controller. After doing that, you need to follow these steps:

In the right pane, locate Enable RPC encryption option and double click it.

Make sure that this option is set to Enabled. Click OK to save changes.

Solution 2 – Add proxy exceptions

Your proxy settings can interfere with Microsoft Exchange and cause this error to appear while starting Outlook 2010. To fix this problem, you need to go to the Internet Options and add your mail server to the Exceptions list. To do that, follow these steps:

After adding the mail server to the exceptions list, the problem with Microsoft Exchange and Outlook 2010 should be completely fixed.

Solution 3 – Add DefConnectOpts DWORD to the registry

This solution is quite similar to the one that we used to fix the problem with Microsoft Exchange and Outlook 2007, therefore we’ll keep this one as short as possible. To fix this problem, start Registry Editor and go to the HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\RPC key. In RPC key create a new DWORD and name it DefConnectOpts. Open its properties and set the Value data to 0. Click OK to save changes and check if the problem is resolved.

If you’re getting The connection to Microsoft Exchange is unavailable error, you should be able to fix it by enabling RPC encryption for Outlook 2013. To do that, first download Office 2013 ADM templates and add them to your domain controller. After that, follow these steps:

Users reported that this issue occurs if the computer can’t find the mail server via Active Directory. You can fix this problem by making a couple of changes in your registry, but before making any changes to your registry, we advise that you back it up. To fix this problem using Registry Editor, do the following:

Open Registry Editor.

When Registry Editor opens, in the left pane navigate to the HKEY_CURRENT_USER\Software\Microsoft\Exchange\Exchange Provider.

In the right pane you need to create a new string value by right clicking the empty space and choosing New > String Value. Enter DS Server as the name of the string.

Double click DS Server to open its properties. In the Value data field enter the address of your global catalog services domain controller.

Close Registry Editor and create a new profile in Outlook.

After changing your registry and creating a new profile in Outlook, the issue with Microsoft Exchange should be fixed.

If you’re getting The connection to Microsoft Exchange is unavailable error while using Outlook 2013, you might be able to fix this problem by downloading Microsoft Office 356 Support & Recovery Assistant tool. After downloading this tool, run it and let it fix any potential problems. Few users reported that this tool fixed the Microsoft Exchange error message on their PC, so you might want to give it a try.

If you’re still having issues on your PC or you simply want to avoid them for the future, we recommend you to download this tool (100% safe and tested by us) to fix various PC problems, such as file loss, malware and hardware failure.

The connection to Microsoft Exchange is unavailable error will prevent you from sending or receiving any emails, but you should be able to fix this problem using one of our solutions.